A conventional rotation angle sensor detects a rotation angle of a detected object using a sensing integrated circuit (IC) that outputs a signal in accordance with a change in magnetic field. The sensing IC includes a magnetism detection element, leads, and a resin molded body that seals the magnetism detection element and the leads.
In a rotation angle sensor disclosed in JP-A-2004-4114 (corresponding to U.S. Pat. No. 6,407,543), a magnet is attached to one side of an axial direction of a detected object that is rotatably held by a housing. In addition, a housing cover made of resin is attached to a side of the housing adjacent to the magnet. A sensing IC that outputs a signal in accordance with a change in a magnetic field due to a rotation of the detected object is sealed with the housing cover, which is molded, and is fixed to the housing cover. Accordingly, the sensing IC is accurately positioned with respect to the detected object.